Attachment for locks



July 14, 1936. v s, D VQMN 2,047,861

ATTACHMENT FOR LOCKS Filed June 26, 1955 2 Sheets-Sheet 1 July 14, 1936. v. s. DOWNING ATTACHMENT FOR LQCKS Filed June 26, 1935 2 Sheets-Sheet 2 5 Ir Eli-$ 7157296 ZSDaw Patented July 14, 1936' ATTACHMENT FOR LOCKS Virgil Sidney Downing, Jackson, Miss;, assigncr of one-third to Joseph W; 'Rcell and one-third to Stewart Gammill, both of Jackson, Miss. pApplicationJune 2c, 1935, Serial No. 28,512

15 Claims. (Cl. 116-8) This invention relates. to attachments for looks;

An object of the invention is the provision of a device adapted to be attached to a lock .for causing an alarm to be set in action when an unauthorized person attempts to enter a room .by a master or skeleton key. 7 Another object of the invention is the provision of a device adapted to be attached to the inner face of a door of a room either in. a private or public building for causing. an alarm to be set in action when some unauthorized person attempts to enter the room. by a master key after a nightlatch has been placed in operative position by theoccupant of the room, no modification of the lock being required for the application of the device since the attachment has elements so constructed that they may be'placed in operative relationiwith the operating cam of thelock. ,7 i r r A further objectof the invention is the provision of'a device whichmay be readilyplaced in operative relation with the-operating cams of a lock whereby an alarm' will'be set inoperation when a master key has been employed for causing'the' reciprocation of a pair of lock bolts from operative relation with the keeper on the door frame, means being employed which is not readily detectable from the exterior for resetting the alarm or forcutting off the alarm'when necessary.

A still further object of the invention is the provision of a device which is form'edas a unit and which maybe readily placed inoperative relation with an operating cam of a lock whereby an arm may be set'in'operation when a mas-' ter key is used for causing reciprocation of the looks from the exterior of a room, said device including a spring-pressed plunger adapted to be adjustably positioned into thefpath of .the cam for releasing the operating mechanism for the alarm when said plunger is rocked by the calm, the plunger being so constructed that the master key may operate the cam in an opposite direc tion for throwing the locking bolt into anoperative position without setting the alarm in action.

Another object of the invention is the provision of a device for creating an alarm to frighten unauthorized persons who are attempting to enter a room by means of a master key which is capable of not only releasing the bolt normally operated from the inside by a knob, but which is capable of throwing a locking bolt connected with a night latch which is normally movedto an operative position by the occupant of a room before retiring. V

This; invention will be best understood from a consideration of the following detailed description, in view of the accompanying drawings forming a part of the specification; nevertheless, it is to be understood that the ,inven-, tion is not confined to the disclosure, being susceptible of such changes and modifications as define no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 is a view in perspective of a door lock attachment constructed in accordance with the 15 1 principles of my invention,

Figure 2 is'a longitudinal vertical section of a lock and the attachment,

Figure 3 is a vertical section taken along the line 3-3 of Figure 4,

Figure 4 is a vertical section taken along the line 4-4 of Figure 3,

Figure 5 is a fragmentary vertical section taken along the line 5-5 of Figure 3,

Figure 6 isa view in perspective of the spring motor,

Figure 7 is a vertical section taken along the line 1] of Figure 2,

Figure 8 is a vertical section taken along the line 88 of Figure 2,

Figure 9 is a vertical section taken along the line 99 of Figure 2,

' Figure 10 is a. horizontal section takenalong the line I 0-I ll of Figure 2,

. Figure 11 is a fragmentary enlarged view in elevation of the tripping means for the alarm, and

Figure 12 is an enlarged view in perspective of the tripping mechanism.

Referring more particularly to the drawings, designates a door which may be used in connection with dwellings, hotels, or apartments and is provided with a lock casing 2| mounted within a pocket 22 formed in the door. This lock is provided with an outer knob 23 which is in the form of a dummy and has no effect whatever on the lock mechanism for shifting the usual lock bolts., V

A knob 24 is located within the room and is adapted to shift a lock, bolt 25inward1y of the metal facing plate 26 on the vertical edge of the door 20 when said knob is revolved whereby the door may be opened from the interior. t

A night latch lock is included within a barrel 21 which is threaded at 28 in an opening in the casing 2|. A face plate 29 is secured to the outer face of the door 20.

The lock barrel 21 is usually of the permutation type so that only a certain kind of key may be inserted in the usual slot in the barrel for operating cylinders which are connected to cam 30 for causing shifting of the lock bolt by a mechanism (not disclosed) and whi'ch forms no part of the present invention. A cam -3f is so associated with the cam that it may be oper shafts 5i and 53 must pass through-these open- 'ing'siandtheipositions of these shafts have been ated by the master key for reciprocatinga belt 32 which had been moved to an operative posie tion with the keeper on the door jambby means of a handle 33 by the occupantofthe'room." {The lock bolt 32, however, is never 'on when .the 1 4 the housing 35 and includes a motor, generally door 2! has been closed and no one is mine room since it is of the type'whichcanonly be shifted to an operative position, on the onehand, by a partial rotation of the member 33 'or on the other handlby the inaster key. I f It should be borne in mind thatfewhen a guest effa hotel'has engaged aroom he is given-a-key WhicH' ma'y beinserted in the slot-in thebarrel 2156i operating-the cam 30 w'hich will reciprocate the' bolt ill from the exterior of the room. Orrthe other handgifthlahotel manager desires to enter the room for some'reason after'th'e lock belt 32 h'asbeen moved toan operative position by-the handle- 33 it' will be necessary for-such person to use a master key- 'which will not only rock the cam 30 but will rock thecam 3l in ad-' Vance of the rocking of the camiilfl so that both lock bolts 2-5 and 3-2 'will beshi'fted to an inoperafive position. 3 r r V All the parts just described relate to standard lock constructions and therefore form no part of the present invention.- My invention, however, is' enclose'd within ahousing generallydesignated by the numeral 35 and is attached to-the inner face of thje door and. normally sealedagainst unauthorized removal although an eleme'nt project's from-thecasing into a spirally construtedmocket 36 of the door 20and isadapted to: be operated by the cam 35 to set an alarm in-operation.

The housing 35 consists of a shallow portion 31 ar id"-'a po'rti'on 38 ot greaterdepth. This housing is provided with a base platepgenei allydesignated by the num'eral 39. .7

The base plate is secured to the :inner -f-ace of the 'doorflll by means'of screws 'flll and this base plate is provided with an outwardly lprojecting bracket l l to wl iich is bolted; as shown. at 42, a bar 43 which is secured'imany :ap proved man! ner to tlie s'idewalls of-- the po'rtion 38 of :the

' housing 35. an win benoted that the bolts 42 are located directly opposite a door 44 which closes' an iopening that prov-ides an entrance to the housing at this point-so that whenthedoor unlocked and ho t uritil then the belts be removed by-a-suitable'tooL' V mateur- 44 is --pr0vic1ed withalock "4'5 Has a l'oek'bolt 46 adapted -to en'gage the in'iier fac'e of the}auxiliary portion 38 'of the housing and preventS the ddol -froii'l being: opened until a sl'ii-tahl Q key has --been inserted in the -S10t 41 o f the door 4'4. M The auxiliary housing, as shown in Fig.4,sis

provided-fwith gui-des f4 'l whichare adapted to recei've a metal plate w ha'ving' advertisinglmatter on its surface-so that the" door 44 together-' with its key slot;Eis norrnally hidden froin view. When the plate flfl -h'as b'een raised or withdrawn the doomcwill'be exposedato view.

' .knob or handle 24. The opening 50 when aligned with the opening at the innerend'of the barrel Z1 and the opening 52 has, been aligned with an opening 54 "in the door 20 will indicate to the workman "that the plate 39 has been properly positioned on the inner face of the door since the previously determined by the position of the lock when originally placed in the door.

fialaiinfis located within the portion 38 of ihdicat'ed-by'the numeral 55, and a bell which as shown in Fig. 2 is secured to a lug 51 carried bytheiriner face of the member 38 and held to 20 said lugisbyn'means of as'crew 58.. a

The motor 55' includes a casing which has 7 lugs. '76 I at i-ts innerp'e'riphe'ry-cooperating with lugs 62=toniaicoveriplate 63 for securingthe cover.

plate:toit-he openend'of the casing. 25

vAisleeveMvistthreaded with left handthreads, as shown at 65, into the outer face 65 of the casing fill -andfisv provided with a shoulder 61 adapted -to'engage the outer face 66.

WA hollow axle -'|0spasses through openings in the cover p1ate 63=andithejouter'face p1ate'66 and isrreceiv ed'bythe sleeve fl which-acts asia bearing' forl'the outer end-of the axle. This axle is formed=integral1y withra base plate H which. is

shown at '12 as secured "to thebase plate. 39 g of the housingv 35... v

As shown more particularly in Figs. 3 andi l; a;-spri ng"l.3:is coiled within the casing 165 and hasuone end'securedto a lug -14 :projecting from the axle 10. The other end of the spring, as'shown at:1 5,':.projects through-an opening '16 -inthe cas ing-rBU and is turned -for securing the outer end ofwthe springto the. casing.

A-winding key 11: is provided with ,an op'erat ing handle andaisad'apted'to be inserted-within'the sleeve 54 so thata diametrically disposed pin 19wvill-be-received within slots in-the outer end of thesleeve-64; Thus when the handle 18 V isjrevolved-the sle'eve will be :revolved and likewiseathe casingxfifl for winding up the spring 13.

A pawl 8| is pivotally mounted at 82 on the V is-rmaintained iin-spacedyrelation with the base platewH-which isconnected to thevbarrel 10 by. meansrof a -washer-86*provided with a fiange 8T whichr-is contact-with -'the;gear and the flange is of sufiicient diameter to maintain the gear. 85 m a predetermined position. i

witjwillbevnoted that the, washer '86, the gear 85, ztheratchet-pwheeb83 and-the cover plate 63 7Q ofithe-casing-GO are provided -with-slots, generally indicated by 'the numeral' 88, to. permit the insertion of the lug 14 into properposition when;these V V elementsvarerplacedon the axle 10.

. the moving discs.

64 is located in alignment withthe door 44; in; the portion 3,8;of the housing 35 sothatwhen the door is unlocked the key I! may be inserted for rewinding the motor.

A series ofgears cooperatively mesh for revolving the shaft 90 as shown in Figs. 7 and 8. The gear 85 meshes with a pinion gear 9| secured to a gear 92 meshing with a pinion gear 93 secured to agear 94. The last-mentioned gear meshes with a pinion 95 secured to the shaft 90 A gear 96 secured to ,the shaft 90 meshes with the ,locking gear 91 carried by the base P1a 39.-.. V I a o A bracket 98 whiohis secured to thebase plate 39 isadapted to support the upper ends of the shafts of the pinion gears 9I and 93. This bracket alsosupports the upper end of the shaft 90 i and this shaft projects outwardly of the bracket plate for receiving a clapper 99 which is in the form of a governor and this governor is housed within the bell 56.

The governor consists of diametrically disposed arms'lflflwhich are connected to the shaft 90 by means of a nut. IN, the governor resting upon a shoulder I02 connected to the shaft 90. As shown more: particularly in Fig. 2, these arms I are spaced apart to receive weighted 'discs I03 which have central openings of greater diameter than lugs I04 so that these discs will be thrown outwardly by centrifugalforce when the arms are being "revolved at a predetermined speed. As these discs are thrown outwardly they alternately strike a lug I 05 which is punched from the metal of the'bell and which projects into the path of I Each of the lugs I04 is struck up from, the :inner arm I00 and projects through an opening I06 at each end of the outer arm I00. A tripping mechanism, shown more particularly inFi gsf1'1and 12, consists of a lever I I0 which is pivoted intermediate its ends, as shown at II I, to the base plate 39. The upper endof the lever is provided" with a notch H2 which is adapted to engage with the teeth of the pinion 91. When the no'tcli'is so engaged all of the gears 9| to 91,

-- inclusive, are held against rotation as is the gear 85 and ithe motor55.

An arm I I3 projects from one edge of the lever II 0 below its pivot III and is provided with a 7 guide I I d-which receives a rod II5. A set screw w and likewise the II 6 secures the rod II5within the guide and in an adjusted position for a purpose which will be presently explained. A stop I I1, secured at II8 to the baserplate 39, is adapted to engage the arm I I3 for limiting the movement of the arm lever H0. The screw and guide are located outwardly of the base plate 39 so that the rod may be adjusted and the screw set conveniently from the exterior. 3

CO V V V plunger I2I and a spring A barrel I the rod projects from theinner end of H5 and carries a slidably mounted I22 located within the barrel tends to force the plunger outwardly. A head I23 is carried by the lower end of the plunger and is provided with a cam face I24 for a purpose which will be presently explained.

A rod I25 is pivotally connected to the lever I I 0 by a pin I26 to which one end of a spring I2! is attached. The other end tached to a pinl28 secured to the base plate 39.

' The rod I25v extends across the base plate and projects through an opening I29 atone'side wall I30 of the housing and also through an opening I 29 in aflange I30 on the plate 39. This rod is providedwith a shoulder I3I..which' is dapt d-t9en e fln s e 1.3 Pi skewer v of the spring is at-.

formed on the inner face of the flange I30 as shown in Fig. 11 for maintaining the rod in its shifted position. Aspring I35 pulls downwardly on the rod I25 and has one end connected at I36 tothe base plate 39 so that the shoulder will be in a position to engage the keeper I33.

The operation of my device is as follows: As has been previously explained the door may be opened from the exterior by means of the regular key given to the guest of a hotel or by a master key. The key carried by the guest, however, will not release both look bolts 32 and 25 but these lock bolts can only be reciprocated by the master key. However, the key held by the guest is suflicient for his purpose since it will release the bolt 25. The night latch by means of. the handle 33 can only be operated from the interior of theroom for moving the bolt 32 into, operative relation with its keeper in the door frame so that the bolt is never in looking position when the guest is out of the room.

After the guest has entered the room and before he retires for the night he will usually revolve the handle 33 and this will cause the bolt 32 to be moved into operative relation with its keeper. The alarm mechanism, however, is in the position shown in Fig. 7 with the rod I25 moved inwardly of the housing 35 so that the notch II 2 at the upper end of the lever II 0 is in engagement with the teeth of the wheel 91. In this position, and with the motor spring wound, the motor will be held against rotation. It is taken for granted, however, that the motor has been wound. This is accomplished by raising the slide plate 49 so that the door may be opened with the proper key and the key 'I'I inserted within the sleeve 54 whereby the spring is wound.

If some unauthorized person should attempt to enter the room while the guest is in the room by means of a master key the cam 3| will be first rotated. When the unauthorized person attempts to operate the look by a master key the cam 3I will immediately engage the head I23, as shown in Figs. 11 and 12 and rock the barrel I20, thereby rocking the lever IIO so that the rod I25 will be shifted outwardly and cause the shoulder I3I to engage the edge I32 of the keeper I33.

As soon as the lever I I0 is rocked the notch I I 2 at the upper end of the lever will be moved out of engagement with the teeth of the wheel 9'! so that the gearing will be free to revolve whence the motor 55 will revolve the ratchet wheel 83, the gear and the train of gears connected with the shaft 90. Since the governor 99 is connected to the shaft the arms I00 will be revolved,

causing the discs I03 to be thrown outwardly and: alternately strike the lug I05 on the bell 56. The

ringing of the bell will warn the guest that somebody is attempting to enter his room. The bell will continue ringing until the spring 13 is unwound since the rod I25 will hold the lever H0 in released position.

'If for some reason the unauthorized person should attempt to turn the key in a reverse direction, thinking that it may be possible to turn oif the alarm, the cam 3| will be rocked likewise in the opposite direction and will engage the inclined face I24 of the head I23 and thus merely move the head upwardly towards the barrel I20 without causing rocking of the barrel or the lever II 0.

The alarm is of sufiicient intensity to frighten the intruder away from the door and a series of perforations I50 are formed in the side wall I 30 of the housing 35 to permit the sound to readily has been set, however, the lever .trically opera-ted motor may on the-door jamb sotha-t it is escape from said housing. In order" to reset the alarm it is only'neces'sary for the operat0r=--to raise the. projecting end of the rod I to release itfrom the catch l3'3 whereby the spring 121-- will return the. lever Hi) to its operative position and cause the notch H2 to engage the teeth of ,the wheel-91. I a 5 Thenplate. G9: is raised and when the: 'door- 44 has beenunlocked the key Tl may be inserted and the spring wound to an operative position. i

The earns and. 3| are of'the usual construction in this form of lock mechanism andlboth of these cams must be revolved for releasingfirst the lock bolt 32 and then the lock bolt 25. An authorized person who isfamiliar .with the alarm may readily release the alarm by raising the outer end of the rod I25 to out 01f the motor. The

lock bolts 32 and '25, however, can only be oper-.-

ated from the outside by the usual master key for the purpose.

The base plate 39 is secured to the inner'face of the door by a plurality of screws '40. Since the cover plate or housing is securedto theba'sei plate'by means of the screws or bolts lizait'lis not possible forsomeone to remove the cover plate or housing without unlocking, thedoor- 44. .Itwillbe noted thatevery precaution has been taken for preventing unauthorized persons from inspecting the interior of the mechanism without destroying certain parts. a

The shaft 5| isflat'and is: adapted'toibe re:- cei ved within passagesin'thecams 39 and3i. The pin 33" is diametrically disposed in the shaft. 5| and extends upon .opposite sides of the same". andis adapted to engage the inner face ofthe cover plate 35 so that the shaft and handle 33 form a unit with the coverpl'ate and may be removed with said cover plate; The openings and 52 in the base plate 39 determine the'proper: positioning of the base plate on the inneriiace of the door so that when the opening 5fll'is aligned; with the openings in the cams 38 and 3 i: and the opening 52 is in line with the opening. 54 in the door2fl, the base plate has been-properly post-e tioned. a v 1 Instead of the spring-wound motor55,1an elecbe substituted and the lever I Hi when rocked by the plunger 121 will close a circuit to the motor. The closing ofthe circuit may also warn the clerkat-the desk that some unauthorized person is attempting to enter the room. I

When the master key is revolved in onev direc:- tion it'will rock the cam 3 I in thesame direction and thereby release the bolt 32. 'When the alarm H6 willbe re-' leased through the rocking ofthejplunger I2 I and cause the alarm to be operated. l fi however, the. operator turns themaster key in the opposite-Ili rection the cam 3| will ride beneaththe inclined: face of the plunger l2l and. force the same into: the barrel against the tension of the spr ihgwithaout rocking the lever. This reverse'movernentlof the masterkey, howeverfwill throw-the locking bolt 32 into an operative position witn' the keeper possible for a hotel detective or watchman to throw this bolt. to operative position without disturbing the alarm. While the key hastb'een define'd'% amasterkey it can be more properly described-as an "ein'era gency key which is owned by the hotel or other tenanted building and is adapted to- 'be"usedsome authorizedperson in the" building tounlo'ck the door when" the tenant or guest'is in reem and fails'to respond to 'calls' in the usualmanner:

will be set for operation when It: isundrstood, however; that thegaest has V turned'the knob 33 and thrown theau x iliaryf keeper in place whereby "the" mechanism I 'theemergeneykey is employed froni-the exterior ofthe room. 1

I-elaim: '1. In alock-having a cam adapted te be rocked by a master key onlyifor releasinga lockingbolt,

the combination of a motor, an alarm actuated by I the motor, means for retaining the motor' against operation-, ,and'means in the path of themoving cam adapted tobe rocked bysaidcam and operatively connected with the last -mentionedfmeans for releasing the retaining-means.

2. In a lock-having a cam adaptedtobe rocked: by amaster key only for releasing a lockingbolt,

the combination of a motor, an alarm actuated by the motor, alever having means for retaining the motor' against operation 'and means con nected with the-lever and rocked by the cam for releasing the retaining means.

' 3. In a lock-'having'a cam adapted to be rooked by a master key only for releasing a locking bolt, the combination oran-alai'm, means for operating the alarm, means for restraining the operating means,'and atrip means actuated byth'e rockable clam-for causingrelease'of th erestraining mean's; and means at the room si'de of the lockior causing shifting of the bolt to locking position.

4. Ina lock having' a cam adapted to brock'ed by a masterkeyonly forreleasing a'locking bolt, the combination of'analarm, means forjopera't ing the alarm, means for restrainingtheoperat ingmeans, a trip means-actuated by the rockable c'am for causingreleaseof the restraining means; and means f or retaining the" restraining'means an inoperative position." V Y 5. In alock having a cam adapted tobe rocked only bya master key for releasing a locking bolt,

the combination of an alarm, an operatingm'eans for the alarmra pivotally mounted "lever, meanson'the' lever engageable with an element {of the operating'means'for retaining theoperating means inactive; means located in the path of the'rocl'b,

able cam connected withthe' leverandadapted'to be rocked by the cam for movingthe leverto'a'ninoperativeposition, and meansfor retainingsaid' lever in theinoperative positio'n.

" 6; In a lock having la canr adapted to be rocked only by a master key "for releasing a locking" bolt,

the combination of an-alarm, an operating means for the alarm, a pivotallymountedlever,-means on the lever 'engageable with an element of the operating means for retaining the operating meansinactive, means located in the "path of r the rockable cam, connected with" the" lever; and

adapted to be rockedby the cam for moving the lever to an inoperative position, a rod having'o'ne end pivotallyconnected to the lever, and 'a latch means for retaining the rod against movement when the lever has been rocked;

'7. Ina lock having a cam adapted to'berocked y' y' 3L1 a te key for releasing .alockin'g bolt, the combination of an alarm; a motor, an acme ating meansforthe alarm;ja:'gear train operatively connected between the'actuating means and the mot'orya pivotally mounted lever having; means 'engag'eable with one of the gearsof the train for: retaining the motoragaihst operation;

and means actuated by thecam" for causing Tielease 'ofltheleve'r when the 'camis rocked;

18', Ina: 'ck having'a cam adapted to'be'roeke'di only by; a' master key 'for releasing a lockihgibolt, the combination offan' alannyamotor, an'ac'tuat ing nieans'for the" alarm, z'axgear train operatively 7J5 connected between the actuating means and the motor, a pivotally mounted lever having means engageable with one of the gears of the train for retaining the motor against operation, means actuated by the cam for causing release of the lever when the cam is rocked, and means actuated by the lever for retaining the lever in an inoperative position.

9. Ina lock having a cam adapted to be rocked only by a master key for releasing a locking bolt, the combination of an alarm, a motor, an actuating means for the alarm, a gear train operatively connected between the actuating means and the motor, a pivotally mounted lever having means engageable with one of the gears of the train for retaining the motor against operation, means actuated by the cam for causing release of the lever when the cam is rocked, a rod connected to the lever and moved by the lever when rocked, and means for releasably retaining the rod and likewise the lever in position when said lever has been moved to an inoperative position.

10. In a lock having a cam adapted to be rocked only by a master key for releasing a locking bolt, the combination of an alarm, a base plate for supporting the alarm, a motor for operating the alarm, a lever pivoted on the plate and adapted to retain the motor against operation, an arm projecting from said lever and provided with a barrel, a spring-pressed plunger projecting from the barrel and into the path of the cam, said cam engaging the plunger when rocked in one direction for oscillating the lever to release the motor, and means for releasably retaining the lever in an inoperative position.

11. In a lock having a cam adapted to be rocked only by a master key for releasing a locking bolt, the combination of an alarm, a base plate for supporting the alarm, a motor for operating the alarm, a lever pivoted on the plate and adapted to retain the motor against operation, an arm projecting from said lever and provided with a barrel, a spring-pressed plunger projecting from the barrel and into the path of the cam, said cam engaging the plunger when rocked in one direction for oscillating the lever to release the motor, the projecting end of the plunger having a cam face adapted to be engaged by the cam when rocked in the opposite direction so that the plunger will be forced into the barrel without moving the lever.

12. In a lock having a cam adapted to be rocked only by a master key for releasing a locking bolt, the combination of an alarm. a motor for operating the alarm, means for retaining the motor against operation including a rockable lever, a barrel carried by the lever, a springpressed plunger in the barrel and having an end projecting across the path of the rockable cam, said plunger and likewise the lever adapted to be rocked by the cam for releasing the retaining means, said plunger having an inclined face over which the cam will ride in one direction of rotation and force the plunger into the barrel so that the bolt may be shifted into locking position without rocking the lever.

13. In a lock having a cam adapted to be rocked only by a master key for releasing a looking bolt, a base plate, an alarm, means for operating the alarm, means for retaining the oper-, ating means against motion including a pivoted lever, a rod pivoted to the lever, said rod having a shoulder, a catch on the base plate adapted to engage the shoulder and retain said rod in an operative position, resilient means tending to move the rod to an inoperative position and the lever to an operative retaining position for the lever, and means connected with the lever and rocked by the cam for moving the lever to an inoperative position.

14. In a lock having a cam adapted to be rocked only by a master key for releasing a locking bolt, an alarm, means for operating the alarm, means for retaining the operating means against motion and including a rockable rod, a guide for the rod, a plunger connected to the rod and adapted to be rocked by the cam, means for adjustably positioning the rod in the guide so that the plunger may be properly positioned in the path of the rockable cam.

15. In a lock having a cam adapted to be rocked only by a master key for releasing a locking bolt, means at the room side of the lock for causing shifting of the bolt to locking position, a base plate, a housing removably secured to the plate, a clapper mounted on the plate, a bell secured to the inner wall of the housing and adapted when the housing is in place to enclose the clapper, means for operating the clapper, means actuated by the cam for setting the operating means in motion.

VIRGJL SIDNEY DOWNING. 

